From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cyrill Gorcunov <gorcunov@gmail.com>
Subject: Re: [patch 2/2] fs, proc: Introduce the /proc/<pid>/map_files/
 directory v12
Date: Fri, 16 Sep 2011 22:07:32 +0400
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Cc: Pavel Machek <pavel@ucw.cz>, Andrew Morton <akpm00@gmail.com>,
	linux-kernel@vger.kernel.org, containers@lists.osdl.org,
	linux-fsdevel@vger.kernel.org,
	Kirill Shutemov <kirill@shutemov.name>,
	Pavel Emelyanov <xemul@parallels.com>,
	James Bottomley <jbottomley@parallels.com>,
	Nathan Lynch <ntl@pobox.com>, Zan Lynx <zlynx@acm.org>,
	Daniel Lezcano <dlezcano@fr.ibm.com>,
	Tejun Heo <tj@kernel.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Al Viro <viro@ZenIV.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>
To: Vasiliy Kulikov <segoon@openwall.com>
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On Fri, Sep 16, 2011 at 09:56:18PM +0400, Vasiliy Kulikov wrote:
...
> > 
> > v14: (by Vasiliy Kulikov)
> >  - for security reason map_files/ entries are allowed for
> >    readers with CAP_SYS_ADMIN credentials granted only
> 
> This changelog is currently much longer than the commit description text ;)

Yes, I know ;) I would like to keep it (to appreciate everyone who spent time
in review and feedback).
...
> 
> > +
> > + inode = dentry->d_inode;
> > + task = get_proc_task(inode);
> > + if (!task)
> > +         goto out_notask;
> > +
> > + if (!ptrace_may_access(task, PTRACE_MODE_READ))
> > +         goto out;
> 
> While this is not needed with capable() check, it's OK to keep it for
> the future more finegranted access checks.

yeah

> 
> BTW, not a big deal, but probably you should return -EACCES on
> !capable() as file presence is not an issue in this case.
> 
>     if (!ptrace_may_access(task, PTRACE_MODE_READ))
>         goto out_notask;
> 
>     status = -EACCES;
>     if (!capable(CAP_SYS_ADMIN))
>         goto out_notask;
> 
>     status = 0;
> 
> 

That's not a proble to fix it actually. So can I fix it and
put some tage here (Reviewed or something?).

	Cyrill